Pen plunger latch



Dec. 28, 1965 E. HECHTLE PEN ,PLUNGER LATCH Original Filed June 28, 1963 I I.. 'l /z/.//Cwmr ///M///////////////w /NVE/V To@ E H IL H EC HTL-E W Alwm/ AT VORNE? United States Patent C 2 Claims. (cl. 12o-42.03)

This invention relates to a ball-point pen wherein a cartridge may be projected or retracted and more particularly to a plunger latch for projecting the cartridge of such a pen. This application is a division of application Ser. No. 292,209, lled June 28, 1963, and is an improvement of the plunger latch shown in co-pending application Ser. No. 130,851 filed August 11, 1961, now Patent No. 3,143,101.

In my parent application, I provide a multi-cartridge pen with an individual cartridge project-retract mechanism that is easy to assemble, employing a minimum number of parts in a minimum amount of space, and having a onepiece combined cap and barrel into the mouth and top of which the project-retract mechanism supporting structures are inserted to complete the assembly.

The project-retract mechanism for each cartridge in the multi-cartridge pen is operated by a spring which urges a plunger provided with a latch, from the project to the retract position, where it is stopped by a catch. If the spring is too strong or the latch too weak, the parts may accidentally be expelled out of the top of the barrel.

Accordingly, it is an object of the invention to provide an improved plunger latch for the operating mechanism to insure that it will operate successfully when moving the cartridge from the project to the retract position.

Another object is to provide a plunger latch that is hollow and forms a frame of support during its operation. A further object is to provide a plunger latch which is hollow for substantially its entire length while providing a curvilinear support throughout its length for maintaining the plunger in perfect alignment in the pen barrel.

I accomplish these and other objects and obtain my new results as will be apparent from the device described in the following specification, particularly pointed out in the claims, and illustrated in the accompanying drawing in which:

FIGURE 1 is a side elevation of a multi-cartridge pen showing a preferred form of plunger latch;

FIGURE 2 is an exploded view of the pen showing the various constituent parts in perspective; and

FIGURE 3 is a longitudinally sectioned view with one of the cartridges projected into writing position.

Referring more in detail to the drawing, reference numeral 10 designates a one-piece combined cap and barrel having an opening 12 into which a multi-cartridge supporting unit 14 is inserted. The barrel is provided with a ball point opening 16, and a seat 18 for positioning the unit.

The multi-cartridge unit comprises a longitudinally extending separator 20, terminating in a transversely extending spacer 22 forming a transverse support for the cartridges. The separator is preferably molded integrally with the spacer. The separator divides the upper barrel compartment 23 into the number of chambers corresponding to the number of cartridges employed. In the embodiment illustrated, a two cartridge unit is utilized by way of example, containing cartridges 24 and 26.

The separator 2l) constitutes a thin diametric wall extending from the spacer to the outside of the opening 12 where it separates the plungers 23 and 30, used for operating the cartridges. Stops 23 and 25 are formed on the r3,225,746 Patented Dec. 28, 1965 ice opposite sides of the separator for a purpose hereinafter described.

The plungers are hollow and the outer wall of each is slotted as at 32 to form a frame for a springy leg 34 having a latch 36 extending from the end thereof. The base wall 37 is used as an auxiliary catch to engage the stops, insuring that the plungerl will not move there beyond. The outer wall of the plunger is curvilinear to conform to the inner surface of the barrel.

The barrel of the pen illustrated is formed adjacent each cartridge with two catch openings 38 and 40 representing the project and retract positions respectively of the cartridges. `The latch 36 springily engages the wall edge of each opening to snaplock the corresponding plunger therein when in either of the two positions. Springs 42 and 44 encircle the cartridges for biasing the cartridges against the respective plungers. Ears 46 extend laterally from each cartridge to engage the associated spring which rest on the spacer 22. The pressure is thus exerted on each plunger, causes the latch 36 to engage the corresponding opening to which the plunger has been propelled.

The spacer end 23 tits into slot 19 on the pen body so as to automatically orient the plungers with respect to the catches 3S and 40 when in assembled position.

Openings 48 and 50 are provided in the spacer 22 through which the cartridges extend. The openings are spaced suiciently apart to permit the separator to extend from the spacer. The springs rest on the anges 49 and 51 formed at the bottom of openings 48 and 50, respectively.

The project-retract mechanism comprises the plungers operating against the action of the cartridge springs. The unit and separator are inserted into the barrel, until the spacer reaches the seat 18. The cartridges and associated springs are then inserted and thereafter the plungers. The plungers are individually depressed until the respective latches are located in the catch openings 40 constituting the retract position. In this position the springs are under suiicient pressure to hold the entire assembly secured in position in the barrel. The tapered shape of each stop along the upper surface permits the plungers to be cammed past the stops until the base wall 37 snaps past the stop thus enclosing the stop in the hollow plunger.

Upon selecting the cartridge to be projected, the corresponding plunger is depressed, causing the respective latch to be cammed out of catch opening 40 until it reaches catch opening 38 where the latch will engage the wall thereof, against the action of the spring.

When it is desired to retract the cartridge, the latch is depressed in opening 38 by a linger until the latch is free of the wall of the barrel. The cartridge encircling spring will then drive the plunger away from opening 38 until the latch reaches opening 40. At this point the latch 36 will project itself through the opening 40 engaging the wall thereof.

Should the latch be propelled beyond the opening 40 without catching, due to the excess power of the spring and because the latch does not spring into position fast enough, the stop 23 or 25 will engage the plunger of the base wall 37, impeding further motion, and preventing loss of the plunger.

The latch 36 is provided with a camming surface 39 to allow the catch to be inwardly sprung to free it from its respective opening when the plunger is depressed.

The inner barrel surface 52 is tapered adjacent the ball point opening 16, to cam the cartridge slightly olf its longitudinal position enabling the ball point to enter the opening. The cartridge may be made flexible, or the openings 48 and 50 in the spacer 22 may be slightly elongated to permit the cartridge to tilt slightly when entering the central opening.

The plunger may be made of springy plastic with the latch outwardly biased in position, to provide the necessary snap action when the latch reaches the catch opening. The hollowed portion 41 formed in the plunger will permit the latch and stop to be accommodated within the plunger without interference when the latch is depressed or when the plunger is moved into operating position.

The barrel opening 38 corresponding to the project position of the cartridge, may be externally grooved, as at 54, to permit the tip of the finger to be guided against the latch, to facilitate depressing and unlatching the plunger. This convenience is not necessary in upper catch opening 40 from which position the latch is normally disengaged by direct axial pressure on the plunger. The type project-retract mechanism shown requires a minimum of space in the barrel. Other mechanisms may also be employed where the overall diameter of the pen barrel is not controlling.

Because of the stop feature, the cartridge, springs, separator, spacer and plunger are all removed as a unit.

The multi-cartridge pen is exceptionally easy to assemble and operate. However, because of the auxiliary stop feature on the separator, when it is necessary to replace a cartridge, the entire multi-cartridge unit 14 must be removed. This may be accomplished by depressing both latches 36 simultaneously, to `free the unit from the barrel. Alternatively the multi-cartridge unit 14 may be slightly rotated in the seat 18 when all the latches are positioned in the catch openings 40. This rotation will laterally release the latches from the catches permitting the multi-cartridge unit to slide longitudinally and outwardly in the barrel. The catches 40 may be laterally grooved on the inside of the barrel to permit such camming action, or the latches may be provided with lateral camming surfaces for this purpose.

The clip 56 may be molded to the one-piece combined cap and barrel when forming the same. The separator provided with the auxiliary stops prevents loss of a plunger, associated cartridge and spring, should the latch accidentally by-pass the upper catch opening for any reason.

The stops do not eliminate the need for the upper catch openings, since these serve also to anchor the assembly of spacer, separator cartridges, springs and plunger within the one-piece combined cap and barrel. Should one of the plungers fail during a retract operation this function will be maintained by another latch and catch since only a single cartridge can be operated at one time through the barrel opening 16.

The position of the stops on the separator is such that they will engage the plungers at the point when the latches engage the upper catch openings.

The hollow plungers are light in weight without loss of strength. Thus there is a saving in material.

The curvilinear surface of the plunger latch conforms to the inner surface of the barrel to support the plunger in perfect alignment therein.

The stops are tapered on the upper surface to permit forcing a plunger over the stop when inserting cartridges. The stops are positioned on opposite sides of the separator, and off-set from the center thereof so as not to be directly positioned back to back to permit the separator to ex slightly when the plunger moves over the taper of the stop.

The plunger latch is free to swing in an arc corresponding to the entire depth of the plunger for maximum flexibility and freedom of movement.

I have thus described my invention, but I desire it understood that it is not conned to the particular form or use shown and described, the same being merely illustrative, and that the invention may be carried out in other ways without departing from the spirit of my invention, and therefore I claim the right to employ all equivalent instrumentalities coming within the scope of the appended claims and by means of which objects of my invention are obtained and new results accomplished since the particular embodiment herein shown and described is only one of the many that can be employed to obtain these objects and accomplish these results.

I claim:

1. A cartridge positioning member for a ballpoint pen having a barrel provide-d with a catch comprising a longitudinally extending body having a passageway, said passageway dened by two longitudinally extending legs connected by a cartridge positioning means, and a resilient arm extending into the passageway from the body with a free end formed into a spring biased latch causing the latch to engage the catch of the barrel when in proper position, said latch deectable into the passageway in a transverse direction, said passageway extending across the entire body in the same direction as the latch deflection for allowing the latch full deflection across said body without interference, said longitudinally extending legs and connecting cartridge positioning means dening a frame continuously about an opening through which the passageway extends.

2. The cartridge positioning member of claim 1 wherein the body is hollow and semi-cylindrically shaped having two oppositely positioned end walls to form a trough shaped member.

References Cited by the Examiner FOREIGN PATENTS 12/1959 France.

8/ 1957 Great Britain. 

1. A CARTRIDGE POSITIONING MEMBER FOR A BALLPOINT PEN HAVING A BARREL PROVIDED WITH A CATCH COMPRISING A LONGITUDINALLY EXTENDING BODY HAVING A PASSAGEWAY, SAID PASSAGEWAY DEFINED BY TWO LONGITUDINALLY EXTENDING LEGS CONNECTED BY A CARTRIDGE POSITIONING MEANS, AND A RESILIENT ARM EXTENDING INTO THE PASSAGEWAY FROM THE BODY WITH A FREE END FORMED INTO A SPRING BIASED LATCH CAUSING THE LATCH TO ENGAGE THE CATCH OF THE BARREL WHEN IN PROPER POSITION, SAID LATCH DEFLECTABLE INTO THE PASSAGEWAY IN A TRANSVERSE DIRECTION, SAID PASSAGEWAY EXTENDING ACROSS THE ENTIRE BODY IN THE SAME DIRECTION AS THE LATCH DEFLECTION FOR ALLOWING THE LATCH FULL DEFLECTION ACROSS SAID BODY WITHOUT INTERFERENCE, SAID LONGITUDINALLY EXTENDING LEGS AND CONNECTING CARTRIDGE POSITIONING MEANS DEFINING A FRAME CONTINUOUSLY ABOUT AN OPENING THROUGH WHICH THE PASSAGEWAY EXTENDS. 